Lifting-jack



(No Model.) 7

H. STAPLES 82; J. D. LAWTON.

' LIFTING JACK. No. 250,850. 'Patented'Deb. 13,1881.

Wzimav'wx jnvaniom. Q/M @LM wm g UNITED STATES PATENT OFFICE.

HIBAM STAPLES- AND JACOB D. LAWTON, OF BATTLE GREEK, MICHIGAN.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 250,859, dated December 13, 1881.

Application filed May 20, 1881.

1'0 all whom it may concern Be it known that we, HIRAM STAPLES and JACOB D. LAWTON, both of Battle Creek, in the county of Calhoun and State of Michigan, have invented certain new and useful Improvements in Lifting-Jacks; and we declare that the following is a full, clear, and exact description, which will enable others skilled in the art to which it appertains to make and use the same, reference being; had to the accompanying drawings, which form a part of this specification, and in which- Figure I is a detail view, showing all the parts in position. Fig. 2 is a detail view of the sliding bar, working-lever, and connections.

In Fig. 1, A is the foot or base of a liftingjack. B is a notched standard along which slides the bar 0. D is a lever, preferably of the first class, having its fulcrum in the pin E, and connection with bar 0, by hinged arm F.

In Fig. 2, G is a recess-notch in bar 6, so

situated as to receive the fulcrum-pin E at a desired position of lever D, and so allow the bar 0 to be quickly adjusted to any desired height.

The jack is made self-locking by so placing joint I that it will come within a line drawn (No model.)

from pin E to pin H when the lever D is depressed. As will be seen, the notches in standard B give choice of heights from which to work bar 0.

Having thus fully described our invention, we do not claim the chief features or parts broadly; but

What we do claim, and desire to secure by Letters Patent of the United States, is-

1. In a lifting-jack, the combination, with a fulcrum-support, B, of a sliding bar, (I, having a recess-notch, G, so situated as to receive the fulcrum-bearing" E at a desired position of the lever D, so as to allow the free adjustment of bar 0 to various heights.

2. In a lifting-jack, the combination, with standard B, bar 0, and notch G, of ajoint, I, so combined with pins E and H, as to lock the jack when the lever D is depressed.

In testimony that we claim the foregoing as our own we have hereunto affixed our signatures in the presence of two witnesses.

HIRAM STAPLES. JACOB DAVID LAWTON.

Witnesses:

(JHAs. M. LEON, CLIFFORD Hoxsra. 

